public class Computer {
    private String cpu;//cpu
    private String memory;//内存
    public String screen;//屏幕
    String brand;//品牌-->default属性

    public Computer(String brand,String cpu,String memory,String screen) {
        this.brand = brand;
        this.cpu = cpu;
        this.memory = memory;
        this.screen = screen;
    }

    public void powerOn() {
        System.out.println("开机!");
    }

    public void shutDown() {
        System.out.println("关机!");
    }

    public void surfInternet() {
        System.out.println("上网!");
    }
}

